Implantable digestive tract organ

ABSTRACT

An implantable digestive organ is provided for the transport of materials through the digestive tract and in one particular application to an artificial large bowel for replacing all or part of a colon. The prosthetic organ of one embodiment includes an outer support structure, an expandable member or members located within the support structure, and a flexible inner member forming a conduit for passage of material. The inner member is located within the outer member and the expandable member(s) is located between the inner member and the support structure. The expandable members are expanded and contracted, or inflated and deflated to provide pumping action that pumps material through the organ. The prosthesis may also include valves or sphincters at its entrance and/or exit points where material moves into and out of the prosthesis. An implantable pump may be included for inflating and deflating the expandable members in a desired sequence.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/270,179, filed Oct. 10, 2011, which is a continuation of U.S. patentapplication Ser. No. 11/549,573, filed Oct. 13, 2006, now U.S. Pat. No.8,034,118, issued Oct. 11, 2011, which is a continuation of U.S. patentapplication Ser. No. 10/328,446, filed Dec. 23, 2002, now U.S. Pat. No.7,141,071, issued Nov. 28, 2006; all of the aforementioned priorityapplications are hereby incorporated by reference in their entirety forall purposes.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an artificial organ for the transport ofmaterials through the digestive tract and in one particular applicationto an artificial large bowel for replacing all or part of a colon orlarge bowel.

2. Description of the Related Art

A number of diseases or conditions are known to compromise the abilityof peristaltic digestive organs of the body to function. These diseasesor conditions may require resection of all or part of the organ. Suchorgans may include, for example, the stomach, intestines and bowel.

A number of diseases and conditions of the colon or bowel cause thecolon or bowel to malfunction. In some situations such diseases orcondition cause dangerous obstructions in the colon or bowel. In othersituations, gastroparesis may result. Many of the diseases result inchronic or acute inflammation. As a result many diseases or conditionsrequire removal of sections of the colon or bowel or a portion of theilieum of the small intestine.

Crohn's disease is one example of an inflammatory bowel disease in whichthe inner lining of the bowel may become inflamed and cause obstructionsin the bowel. Ulcerative colitus is another example of a disease of thecolon characterized by ulcerations in the colon. Diverticulitis is adisease in which diverticulum of the colon become inflamed, trappingfecal material and potentially leading to obstruction, perforation orbleeding, with fecal material possibly leaking out into the abdomen.Diverticulitis in its most severe form may require resection of theaffected portion of the bowel. Colon cancer, other obstructive growthsmay require significant portions of the bowel to be removed and in doingso may seriously compromise the functioning of the bowel. Anotherexample of a colonl/bowel diseases is toxic megacolon, where the colonbecomes very large and may contain excessive amounts of feces at a giventime.

As noted above, many diseases are treated with colonostomies orileostomies, where all or a portion of the colon or ileum of the smallintestine are removed. Many of these procedures require provision of anartificial stoma in the abdomen for emptying waste from the shortenedfunctioning bowel. Often a pouch secured around the waist by a belt, iscoupled to the stoma and is used to collect the waste. Mortality ratesfor the procedures remain high and for those successfully treated, thepouches are cumbersome to use and manage. Furthermore, the annual healthmaintenance costs for patients who have received this treatment is high.

Artificial sphincters have been proposed to replace failing sphincters.Typically these devices are cuffs to be placed around the outside of anorgan to control the opening and closing of a stoma. Artificialsphincters may be used for example where fecal incontinence is present.This may occur in women as a result of childbirth.

Accordingly it would be desirable to provide a device and method forreplacing all or part of the bowel including in some instances, therectal sphincter.

SUMMARY OF THE INVENTION

The present invention provides an implantable prosthetic organ in whichmaterial is moved through the organ. In one embodiment the prostheticorgan moves material with peristaltic-like movement. The prostheticorgan includes an outer support structure, an expandable member ormembers located within the outer support structure, and a flexible innermember forming a conduit for the passage of material. The flexible innermember is located within the outer member and the expandable member ormembers are located between the inner member and the outer supportstructure. The expandable members are expanded and contracted, orinflated and deflated to provide a pumping action that pumps thematerial through the organ. The expandable members are isolated from thematerial moving through the prosthesis by the inner member in which thematerial is contained. Thus, the material avoids getting caught in theinterstices around the expandable members.

The prosthesis may also include valves or sphincters at the entranceand/or exit points of the organ where material moves into and out of theprosthesis. These sphincters are also isolated from the material by theinner tube.

The organ is preferably an organ of the digestive system having an oradend through which the material enters and an aborad end out of which thematerial exits. The digestive organ of one particular embodimentcomprises a prosthetic large intestine or bowel that replaces all orpart of the large intestine or bowel. According to this embodiment, theouter member of the organ is a flexible tube. The prosthesis may includea valve or sphincter at the entrance (the orad end) and/or a rectalsphincter valve at the exit (the aborad end). A plurality of expandablemembers are arranged to be expanded in a sequence where the expandablemembers are expanded and contracted along the length of the prosthesisto provide a pumping action moving material through the organ. Theprosthesis may work in sections that provide peristaltic movementsaccording to a pattern or sequence of sections. For example an aboradsection may be first actuated, followed by the adjacent section in theorad direction. The aborad section may then be actuated again. Thus, abuild up of material and pressure from the entrance (orad end) to theend (aborad end) is avoided and the material is gradually moved throughthe organ.

The expandable members of one embodiment are balloons or inflatablemembers expandable with an inflation medium. The implantable organfurther comprises an implantable pump system that includes a pump and aprogrammable controller. The implantable pump system in one embodimentalso includes a reservoir of sterile inflation medium used to inflatethe various expandable members. The reservoir may be implantableseparate from the pump, e.g. in soft tissue. In general, the pump systemis a closed system where the inflation medium is stored or passesthrough as it is pumped from one inflation member to another. Eachexpandable member may be configured in a number of manners in which theinflation of the expandable member causes the material in the inner tubeto advance. For example, the expandable member may be configured as aplurality of opposing members that are inflated together through acommon valve. Alternatively, the inflatable member may be in a doughnuttype shape; or the inflatable member may also be staggered from otherinflatable members such that together the inflatable members are in aspiral type configuration. Other patterns may also be used for thepurpose of moving material through the inner tube. Preferably, each ofthe expandable members or groupings of expandable members has an inputport and valve coupled to the pump such that a single valve is opened ata time. However, the system may alternatively have more than one valveopen at a time.

The controller controls the inflation and deflation of the expandablemembers by controlling the opening and closing of the valves coupled toeach of the expandable members, and by controlling the pump direction.In one embodiment, the inflatable members are inflated to apredetermined pressure. The pump may determine the inflation pressure bymonitoring the pumping action or work of its motor. The inflationpressure may also be sensed by sensors that sense the pressure of thesystem, e.g. in the fluid header of the pump system. In one embodiment,the reservoir contains sufficient inflation medium to inflate twosections of expandable members (and if present, the rectal sphincter).According to one embodiment, a first section of expandable memberscorresponding to a first section of the tube is inflated, then a secondadjacent section is inflated. The second section is inflated before thefirst section is deflated so that the material in the prosthesis cannotmove back in an orad direction when the second section is inflated. Thefirst section is then deflated. Then the fluid used to inflate the firstsection is then used to inflate the third section, etc. until eachsection is sequentially inflated.

The controller may also control selection of a section of the organ forthe peristaltic movement. In this regard, sections may be selectedaccording to a desired sequence of the section actuation. The controllermay be preprogrammed to control the peristalsis pattern or may bereprogrammed externally or in response to sensed conditions at variouslocations in the bowel. For example the sensors may sense presence orabsence of material in a section of the bowel and may direct a patternof peristaltic movement in the various sections accordingly.

In one embodiment, a single electromechanical device actuates theopening and closing of the valves according to the sequence. The valveactuator selectively actuates a particular valve at a given timeaccording to instructions from the controller.

The pump and the valve actuating mechanism may be powered through a coilinductively coupled transcutaneously to an external power source, or bya battery rechargeable through such coil and external power source.According to one embodiment, a user positions and actuates the externalpower source to evacuate the prosthesis. The electronics unit may bepowered by a rechargeable or replaceable battery as the controllerconsumes relatively little power in its operation.

The implantable bowel may further include a rectal sphincter valvelocated at the aborad end of the organ. In one embodiment, the rectalsphincter valve includes expandable members configured to close theinner member into an S-shaped configuration. The S-shaped configurationtends to tighten and squeeze the inner member further closed when apressure is applied at either end (orad or aborad) of the valve thuspreventing leakage.

The implantable bowel may also include an orad valve located at the oradend. Preferably the orad valve is a one-way valve that opens to permitsubstance to enter into the inner member of the prosthesis whileresisting backflow of material out of the organ in an orad directionthrough the orad valve. In the case of the colon replacement, the oradvalve may replace the ileocecal valve. In one embodiment of the valve, aplurality of inflated members are inflated to a threshold pressure thatwhen met permits movement of substance through the orad valve into theinner member of the prosthesis. The pressure is generally set to atypical threshold pressure that a small bowel exerts when it iscontracting. In one embodiment of the orad valve, the inflated membersare hinged at the orad end into the prosthesis so that when a pressureis applied from within the prosthesis tube, the hinged balloons tend tocompress towards each other and further close the valve, preventingbackflow of material. In another embodiment, the orad valve may includea combination of a low pressure valve and a high pressure valve wherethe low pressure valve permits the ingress of material into theprosthesis at a given external pressure, and the high pressure valve isselectively closed when the prosthesis is actively pumping materialthrough it to prevent backward movement of the material into the smallbowel.

The implantable prosthetic organ may also include a pressure sensorarranged to sense a pressure corresponding to a pressure within theinner member. The pressure sensor may sense a pressure that indicates toa user the bowel should be emptied, whether from material or gas fillingthe prosthesis. The pressure sensor is coupled to the controller, whichhas a telemetry coil arranged to communicate a telemetric signal with anexternal device. The controller is configured to communicate an alarmsignal to the external device when a pressure sensed by the pressuresensor exceeds a threshold pressure. The external control device maycommunicate via telemetry with the controller, receive the alarm signal,and generate a user perceivable alarm in response to the alarm signal.Upon sensing the alarm, the user may activate the external controldevice which communicates to the controller to release material and/orgas from the device. The controller may also be programmed to gently,partially open the rectal sphincter to release gas, e.g. upon receipt ofa telemetrically 13 delivered user activated control signal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic drawing of an implanted artificial large bowelaccording to an embodiment of the invention.

FIG. 2 is a schematic of an artificial large bowel, pump, valve actuatorand controller of an embodiment of the invention in a resting state.

FIG. 2A is a cross section of FIG. 2 along the lines 2A-2A.

FIG. 2B is a cross section of FIG. 2 along the lines 2B-2B.

FIG. 2C is an enlarged view of a portion of the artificial large bowelof FIG. 2 illustrating the wire sensors.

FIG. 3 is a schematic of the artificial bowel of the embodiment of FIG.2 during a first step of emptying the bowel in which the first inflationmember of the rectal sphincter is deflated and the fluid is stored inthe bladder.

FIG. 3A is a cross section of FIG. 3 along the lines 3A-3A.

FIG. 4 is a schematic of the artificial bowel of FIG. 2 during asubsequent step of emptying the bowel where a first inflation member isinflated with the fluid stored in the bladder.

FIG. 5 is a schematic of the artificial bowel of FIG. 2 during a furtherstep of emptying the bowel where fluid is emptied from a secondinflation member of the rectal sphincter.

FIG. 6 is a schematic of the artificial bowel of FIG. 2 during a furtherstep of emptying the bowel where a second inflation member is inflatedwith the fluid stored in the 6 bladder.

FIG. 7 is a schematic of the artificial bowel of FIG. 2 during a furtherstep wherein the first inflation member is deflated.

FIG. 8 is a schematic of the artificial bowel of FIG. 2 during a furtherstep wherein a third inflation member is inflated.

FIG. 9 is a schematic of the artificial bowel of FIG. 2 during a furtherstep wherein the second inflation member is deflated.

FIG. 10 is a schematic of the artificial bowel of FIG. 2 during afurther step wherein the last inflation member is in an inflated stateand the first inflation member of the rectal sphincter is inflated.

FIG. 11 is a schematic of the artificial bowel of FIG. 2 during afurther step wherein the last inflation member is in a deflated stateand the second inflation member of the rectal sphincter is inflatedclosing the rectal sphincter.

FIG. 12A is a schematic of another embodiment of an orad valve of theinvention in a first position.

FIG. 12B is a schematic of the orad valve of FIG. 12 A in a secondposition.

FIG. 12C is a schematic of an alternative embodiment of a two stagevalve in a first position.

FIG. 12D is a schematic of the two stage valve of FIG. 12C in a secondposition.

FIG. 13 is a schematic of an embodiment of the artificial bowel of theinvention in which the bowel is divided into segments, and of a sequenceof segmental peristalsis according to the invention.

FIG. 14 is a schematic side view of another embodiment of an artificialbowel of the invention.

FIG. 15 is a schematic side view of another embodiment of an artificialbowel of the present invention.

FIG. 16 is a schematic of a miniature valve-actuating device forcontrolling the valves of the pump of an embodiment of the invention ina first position with a valve closed and a rotational position in whichnone of the openings of the device are aligned with a valve.

FIG. 16A is an end view of the device as illustrated in FIG. 16 in thefirst position.

FIG. 17 is a schematic of the valve-actuating device of FIG. 16 in asecond position.

FIG. 17A is an end view of the device illustrated in FIG. 17 with thevalve open and an inflation being inflated.

FIG. 18 is a schematic of the micro valve-actuating device in therotational position of FIG. 17 with the valve closed and the inflationmember in an inflated position.

FIG. 18A is an end view of the device illustrated in FIG. 18.

FIG. 18B is a schematic side cross-section of the cylinder and rod ofFIG. 18.

FIG. 18C is a cross section of FIG. 18B along the lines 18B-18B.

FIG. 18D is a cross section of FIG. 18B along the lines 18D-18D.

FIG. 18E is a top view of the cylinder of FIG. 18.

FIG. 18F is a cross section of a portion of the cylinder as illustratein FIG. 18E along the lines 18F-18F.

FIG. 19 is a schematic of another embodiment of an artificial bowel ofthe present invention.

FIG. 19A is a cross section of FIG. 19 along the lines 19A-19A.

FIG. 20 is a schematic of a valve/sphincter of another embodimentaccording to the invention.

DETAILED DESCRIPTION

Referring to FIG. 1, according to one embodiment of the invention, aprosthetic large bowel 30′ with a housing 60′ including a hermeticallysealed pump unit is implanted in a patient's abdomen 200′. The housing60′ may also include a controller for controlling the pump and theprosthesis. The controller may also be implanted separately (in theabdomen or subcutaneously) or located externally of the patient's body,and coupled to the pump by an electrical connector. A bladder 49′ forsupplying inflation medium is implanted in the soft tissue and iscoupled to the pump unit in the housing 60′. Alternatively, the bladdermay be located with the pump unit. An electromagnetic coil forinductively receiving power from an external source may also beimplanted subcutaneously and coupled to the pump.

A schematic of a prosthetic digestive tract organ of one embodiment isillustrated in FIGS. 2-11. The prosthesis includes a large bowel 30, ahermetically sealed pump unit 40 and a hermetically sealed electronicsunit 50 including a controller 51 for controlling the pump unit 40. Thepump unit 40 and electronics unit 50 may be contained in the samehousing such as the housing 60′ illustrated in FIG. 1 or may beseparate.

The large bowel 30 includes an outer tube 31 which comprises an inner 31i and outer layer 310 of material, a series of inflatable member pairs36 a-e, an orad valve 37 an aborad valve or rectal sphincter 38, and aninner tube 32 comprising an inner layer 32 i and outer layer 320 ofmaterial. If the rectal sphincter is functional or if a partial bowelreplacement is desired, the rectal sphincter may not be necessary toprovide in the prosthesis.

The outer tube 31 comprises a flexible, relatively inelastic materialsuch as, for example, polyethylene or polyurethane, and providesstructural support for the prosthetic bowel 30. However, an elasticmaterial may also be used. The inflatable member pairs 36 a-e form abowel emptying mechanism 35. Hinged inflated members 37 a, 37 b locatedat the orad end portion 33 of the prosthetic bowel 30 form the oradvalve 37. Inflatable members 36 f and 36 g form the rectal sphincter 38at the aborad end portion 34 of the prosthetic bowel 30. The inner tube32 comprises a thin-walled, non-elastic flexible material such aspolyethylene or polyurethane. The inside of the inner tube 32 may becoated with an antibiotic surface, such as a silver coating, to reducebacterial growth. The inner tube 32 is attached to the outer tube 31 atthe orad end portion 33 and the aborad end portion 34 of the prostheticbowel 30 (for example, by welding) to provide an isolated conduitthrough which material may pass. The orad end portion 33 of the outertube 31 includes a relatively thicker portion for suturing the outertube 31 to a small bowel or an orad section of the colon that is toremain intact. The inner tube 32 defines a lumen through which materialmay enter from the small bowel or small intestine and exit through theanus. The hinged members 37 a, 37 b forming the valve 37, the inflatablemember pairs 36 a-e forming the bowel emptying mechanism 35 and theinflatable members 36 f, 36 g forming the rectal sphincter 38 arelocated between the outer tube 31 and the inner tube 32. The inner tube32 floats relatively loosely within the outer tube 31 so as to permitmovement including the inflation and deflation of the inflatable memberpairs 36 a-e and inflatable members 36 f, 36 g.

The orad end portion 33 of the prosthetic bowel 30 is sewn onto the endof the small intestine, or in the case of a partial replacement of thebowel, the section of the bowel that is in communication with the smallintestine. If the ileocecal valve is functional or in the case of apartial bowel replacement, the orad valve 37 may not be necessary forthe prosthesis.

The orad valve 37 at the orad end portion 33 of the prosthetic bowel 30is a unidirectional valve through which material may enter into theinner tube 32 for collection and ultimate excretion from the prostheticbowel 30. The unidirectional feature of the valve 37 serves to preventgas or substances from backing into the small intestine from theprosthetic bowel 30. In one application, the valve 37 may replace oraugment the ileo-cecal valve between the small intestine and colon of apatient. The valve 37 comprises hinged members 37 a, 37 b coupled to theouter tube 31 at pivot locations 31 a, 31 b respectively and extendingin an aborad direction from the pivot locations 31 a, 31 b to form aconstricted passage through which material may pass into the prostheticbowel 30. The hinged members 37 a, 37 b are anchored at the pivotlocations 31 a, 31 b so that they can pivotally rotate within the outertube 31, from the locations 31 a, 31 b. The inner tube 32 extends fromthe orad end portion 33 (where it is coupled to the outer tube 31) overthe valve 37, so that materials passing through the prosthetic bowel 30do not contact the valve 37, thus preventing materials from becominglodged in interstices created by the hinged members 37 a, 37 b of thevalve 37. In addition the hinged members 37 a, 37 b and inner tube 32 incombination form a valve-sealing surface. The hinged members 37 a, 37 bare inflated to a threshold pressure that is generally lower than thatexerted by the small intestine when it is contracting to move materialsinto the bowel. Thus, when the small intestine is active and movingmaterials, a pressure is created that pushes the materials into theinner tube 32 through the valve 37. When pressure is created within theinner tube 32 from gases or the pumping action of the prosthetic bowel30 (FIGS. 3-11), the hinged members 37 a, 37 b are pushed by thepressure, back in an orad direction, causing them to converge and closethe valve 37. In this situation, the pressure within the prosthesispresses the inner tube 32 against the hinged members 37 a, 37 b, andresulting pressure on the hinged members 37 a, 37 b causes the valve 37to close or tighten. In the illustrated embodiment, the hinged members37 a, 37 b are inflated to a predetermined pressure.

The bowel emptying mechanism 35 comprises a series inflatable memberpairs 36 a-e attached to the inside of the outer tube 31 between theouter tube 31 and the inner tube 32 along the length of the prostheticbowel 30. Although pairs 36 a-e are illustrated, the number of pairs ofinflation members depend on a selected prosthesis length and size of theinflation member pairs. According to one embodiment, the inflatablemember pairs are approximately 1.5 inches long in an uninflated state,with about 16 pairs for a 24-inch long bowel emptying mechanism. Thelength of the prosthesis may vary from patient to patient depending onthe size of the patient and the amount of bowel to be replaced. Theinflatable members may also be longer or shorter.

Each inflatable member of a pair converges together when inflated, tomove material through the prosthetic bowel 30. Each inflatable memberpair 36 a-e is coupled to and is in fluid communication with acorresponding one of conduits 39 a-e, respectively. Conduits 39 a-e areused to selectively deliver inflation medium to and from inflatablemembers 36 a-e by an implanted pump unit 40.

The rectal sphincter 38 is located at the aborad end portion 34 of theprosthesis where the prosthesis is attached to the anus 202. The rectalsphincter 38 comprises inflation members 36 f, 36 g attached to theinside of the outer tube 31 between the outer tube 31 and the inner tube32. The inflation members 36 f, 36 g are attached on opposing sides ofthe outer tube 31 from each other so that when inflated, the inflationmembers 36 f, 36 g direct the inner tube 32 around in an S-configurationand pinch the inner tube 32 closed. The S-shaped configuration closesthe inner tube 32 in a manner such that if pressure is exerted fromwithin the prosthetic bowel 30 against the inflation member 36 f, itwill cause the inflation member 36 f to further seal together orapproximate any gap between the inflation member 36 f and the inflationmember 36 g, and pinch the inner tube 32 closed further between theinflation members 36 f, 36 g. As such, when the sphincter 38 is subjectto increases in pressure, the possibility of stress incontinence will bereduced. The inflation members 36 f, 36 g are coupled by way of conduits39 f, 39 g respectively to ports 35 f, 35 g in the header 45. Theinflation members 36 f, 36 g may be selectively inflated or deflated bythe pump unit 40 as described in more detail below. In this embodiment,two opposing inflation members are illustrated. However, additionalopposing inflation members may be provided. Furthermore, although theinflation medium is described as being pumped to and from a reservoirinto and out of the inflation members 36 f, 36 g and inflation memberpairs 36 a-e, in an alternative configuration, the inflation members 36f, 36 g of the rectal sphincter 38 act as the fluid reservoir so as topreserve space.

Additionally, one or more of the inflation member pairs 36 a-e may bepartially inflated during the resting stage and may be periodicallymonitored by opening the corresponding valve and sensing the pressurewith the pressure transducer 48. Accordingly, if pressure builds up frommaterials or gas, the controller 51 may provide an alarm or feedbacksignal telemetrically to an external device, which causes a userperceivable alarm. The user then may proceed to actuate the device forevacuation. In one embodiment in order to release gas, the externaldevice may be actuated to deliver a control signal via telemetry to thecontroller 51, which in turn opens the rectal sphincter valve 38 bypartially emptying the inflation members 36 f, 36 g by controlling thevalves 46 f, 46 g and the pump 41. The pump 41 gradually and partiallypumps fluid from the inflation members 36 f, 36 g to release gas. Thepump 41 then pumps fluid back into the inflation members 36 f, 36 g.

As illustrated in FIG. 2, a controller 51 of an electronics unit 50controls the implantable pump unit 40 to selectively inflate and deflateinflatable member pairs 36 a-e and inflatable members 36 f, 36 g. Thepump unit 40 includes a bi-directional hydraulic pump 41 having anintake 47 coupled to a fluid reservoir 49 and an output 44 in fluidcommunication with a header 45 having fluid ports 45 a-g. Thebi-directional pump 41 may be configured in a number of ways to providepumping in two directions, for example, by controlling a series ofvalves that direct fluid into or out of the reservoir 49 or by providinga DC powered reversible pump. The fluid reservoir 49 contains a sterile,radiopaque inflation medium sufficient to inflate two pairs of inflationmembers 36 a-e, two inflation members 36 f, 36 g or a combinationthereof at a given time. The fluid reservoir 49 may be implanted at alocation adjacent to or away from the pump unit 40 (e.g. in softtissue).

Each fluid port 45 a-g is coupled to a respective valve 46 a-g, which iscoupled to a respective conduit 39 a-g. Each conduit 39 a-g is coupledto a corresponding inflation member pair 36 a-e or inflation member 36f, 36 g. The valves 46 a-g are controlled by a valve actuating device300 which operation is controlled by an electronics unit 50 of thecontroller 51. The valves 46 a-g in this particular embodiment arecontrolled by a electromechanical device described in more detail withreference to FIGS. 16-18F. Alternative valve actuating mechanisms arealso contemplated, for example, individually operated bistable solenoidvalves may be used.

A pressure transducer 48 is located between the output 44 of the pump 41and the header 45. The pressure transducer 48 senses the pressure of thefluid of a particular section of inflation members when thecorresponding solenoid valve of the corresponding port is in an openposition. The pressure transducer 48 is coupled to the controller 51,which controls the pump 41 in response to a sensed pressure.

The electronics unit 50 includes a controller 51 and a battery 52powering the controller 51. The controller 51 is programmed to controlthe action of the various elements of the prosthesis and to respond tovarious sensed conditions. The controller 51 is coupled to the pump unit40 and controls when and in which direction the pump 41 is actuated. Thecontroller 51 is also coupled to a valve-actuating device 300 that opensand closes the valves 46 a-g according to a program stored in thecontroller 51, thereby sequentially inflating and deflating inflationmember pairs 36 a-e and inflation members 36 f, 36 g. According to oneembodiment, only one valve is opened at a time. The controller 51 alsoincludes a telemetry coil 54 for communicating information to andreceiving information from an external device. The external device maybe used to program operation parameters into the controller 51. Theexternal device may also receive signals from the controller 51 orelectronics unit 50 representative of various sensed conditions, e.g.,pressure or system leaks. The external device may program or reprogramthe controller 51 based on sensed parameters or other patientconditions. An external device may also power the pump 41 and thevalve-actuating device 300 through an electronics unit 70 comprising anelectromagnetic coil 71 for inductively receiving power from an externalsource. The electromagnetic coil 71 is coupled to the electronics unit50 which included a voltage regulating circuit. The electronics unit 50and controller 51 control the pump 41 by powering the pump 41 and bycontrolling the valve actuating device 300. The voltage regulatingcircuit in the electronics unit 50 operates to convert a high frequencyAC signal to a regulated voltage signal that powers the pump 41 andvalve actuating mechanism 300. Alternatively, coil 59 may be used forboth powering the pump and electronics unit 50 and for bi-directionaltelemetry communication.

The prosthetic large bowel 30 is illustrated in FIG. 2 in an inactiveposition in which it is collecting waste material from the small bowel201 to which it is attached at the orad end portion 33. In this positionthe rectal sphincter 38 at the aborad end portion 34 is in a closedposition with inflation members 36 f, 36 g inflated. The inflationmember pairs 36 a-e of the bowel emptying mechanism 35 are relaxed anddeflated. The orad valve 37 is free to open to permit the ingress ofwaste material when there is sufficient pressure in the small bowel 201.

The prosthetic bowel 30 also further includes wires 55 a-f (FIG. 2C)embedded in the prosthetic bowel 30 along its length and communicatingwith the electronic circuit 50. The wires 55 a and 55 d are located inthe outer tube 31 each between layers 31 i and 310 and on opposing sidesalong the prosthetic bowel 30. Wires 55 b and 55 e are exposed betweenthe inflation member pairs 36 a-e and the outer tube 31 on opposingsides along the prosthetic bowel 30. Wires 55 c and 55 f are located inthe inner tube 32 along the bowel 30 between layer 32 i and 32 o. Wirepairs 55 a and 55 d form an open circuit as do wire pairs 55 b and 55 e,and wire pairs 55 c and 55 f. The electronic circuit 50 is configured tosense a large drop in impedance in one or more of the pairs wires 55a-f, where a fluid closes the circuit of one or more of the wire pairsindicating potential leakage of fluid into, out of or within the bowel30, e.g. from material external the prosthetic bowel 30, materialpassing through the inner member 32 of the bowel 30 or from an inflationmember, or otherwise. In particular, a low impedance may be detected bythe controller 51, which is configured to sense impedance changes in thewires 55 a-f. The impedance of the pairs of wires 55 a-f is periodicallymonitored by the controller 51. If a leak is detected a patient alarmmay be triggered, e.g., by telemetrically delivering an alarm signalfrom the electronics unit 50 to an external device. Furthermore, thelocation or cause of the leak may be determined by which sires 55 a-fhave changed impedances. The wire pairs may be placed in differentconfigurations within layers 31 i, 31 o, 32 i, 32 o or between the inner32 and outer members 31, for example, they may be is parallel spiraledconfigurations to maximize the sensing of potential leaks.

The prosthetic bowel 30 also includes a conduit 56 through theprosthetic bowel 30, into a port 57 inside the inner tube 31 forreceiving an antibiotic material from a reservoir 58. The reservoir 58is coupled to the controller 51 and may include a pump controlled by thecontroller 51 that provides a periodic or otherwise actuated (e.g. by apatient) injection of antibiotic material or gas dissolving materialinto the inner tube 32.

FIGS. 3-11 illustrate a sequence of emptying the bowel 30 of oneembodiment of the invention. In FIG. 3, the inflation member 36 f of therectal sphincter 38 is emptied through the conduit 39 f by opening valve46 f. The pump 41 pumps the inflation medium out of the inflation member36 f and into the reservoir 49, which is then partially full. The valve46 f is then closed.

Next as shown in FIG. 4, the valve 46 a is opened and the pump 41 pumpsinflation medium from the reservoir 49 into the inflation member pair 36a through the conduit 39 a. The inflation member pair 36 a is inflatedto a predetermined pressure as sensed by pressure transducer 48 oralternatively as sensed by the motor. Once the inflation member pair 36a is inflated, the valve 46 a is closed by the valve actuating mechanism60 (FIG. 2). Inflation of the inflation member pair 36 a closes thevalve 37 on the orad end portion 33 due to the pressure from theinflation of pair 36 a. Waste material is moved in an aborad directionwithin the inner tube 32, due to the mechanical movement of theinflation member pair 36 a and any pressure gradient resultingtherefrom.

Next, as shown in FIG. 5, the rectal sphincter 38 is completely openedby opening the valve 46 g and pumping the fluid from the inflationmember 36 g through conduit 39 g and into the reservoir 49. Thusmaterial is permitted to exit through the rectal sphincter 38.

As illustrated in FIG. 6, inflation member pair 36 b is next inflated toadvance material through the prosthetic bowel 30. Before the adjacentinflation member pair 36 a is deflated, the inflation member pair 36 bis inflated by opening the valve 46 b and inflating by pumping fluidfrom the reservoir 49 that was pumped out of the inflation member 36 g,into inflation member pair 36 b through conduit 39 b. Thus, anymaterials are moved further in the aborad direction without allowing thematerial to move back in the direction of the inflation member pair 36a. The valve 46 b is then closed.

Referring to FIG. 7, the valve 46 a is selected again. The pumpdirection is reversed and the inflation medium is pumped out of theinflation member pair 36 a and is returned to the reservoir 49. The oradend portion 33 of the prosthetic bowel 30 is isolated from the materialmoving through the inner tube 32 by the inflation member pair 36 b. Thevalve 46 a is then closed.

Referring to FIG. 8, inflation member pair 36 c is next inflated toadvance material further through the prosthetic bowel 30. Before theadjacent inflation member pair 36 b is deflated, the inflation memberpair 36 c is inflated by opening the valve 46 c and inflating by pumpingfluid from the reservoir 49 into inflation member pair 36 c throughconduit 39 c. Thus, any materials are moved further in the aboraddirection without permitting the material to move back in the directionof the inflation member pair 36 b. The valve 46 c is then closed.

Referring to FIG. 9, the valve 46 b is selected again, the pumpdirection is reversed and the inflation medium is pumped out of theinflation member pair 36 b and is returned to the reservoir 49. The oradend portion 33 of the prosthetic bowel 30 is isolated from the materialmoving through the inner tube 32 by the inflation member pair 36 c. Thevalve 46 b is then closed. A number of inflation member pairs may beprovided in the prosthetic bowel 30 and the sequence of inflating anddeflating the inflation members continues until the last inflationmember pair 36 e is inflated.

As illustrated in FIGS. 10 and 11, after inflation member pair 36 e isinflated and subsequently inflation member pair 36 d is deflated, theremaining material is advanced through the rectal sphincter 38 and thesphincter 38 is closed by first inflating the inflation member 36 f byopening valve 46 f and pumping inflation medium from reservoir 49through conduit 39 f. The inflation member pair 36 e is deflated byopening valve 46 e and pumping the inflation medium into the reservoir49. (FIG. 10) The valve 46 e is closed and valve 46 g is opened and theinflation medium from the reservoir 49 is pumped into the inflationmember 36 g to close the valve 38.

This cycle of inflating and deflating inflation members may be repeatedin subsequent bowel emptying steps or sequences. The cycle may also bemodified and the order of emptying along the length of the prostheticbowel may be done is subsections according to a program, such as forexample, as illustrated in FIG. 13. Referring to FIG. 13, a sequence ofemptying of one embodiment is illustrated. According to the embodiment,a prosthetic bowel 330 is illustrated as being divided into fivesections, Sections A-E with section A being the aborad most sectioncoupled to the anus and section E being coupled to the small intestine.Each section includes a series of inflatable members such as, forexample, the inflatable members of the prosthesis described with respectto FIGS. 2-11. As illustrated in FIG. 13, the sections of inflatablemembers are actuated in a sequence of sections. In the first sequence I,section A is actuated so that the inflatable members are inflated in asequence in an aborad direction, excreting the material in section A.

After A is actuated, a second sequence II of inflatable member sectionsis actuated in which section B is actuated so that the inflatablemembers of section B are inflated in a sequence in an aborad directionand then section A is actuated inflating inflatable members of section Ain an aborad direction. Thus, material is moved through sections B, thenA and then is excreted.

A third sequence III of inflatable member sections is actuated in whichsection C is actuated, then section B is actuated and then section A isactuated. Thus material is moved through sections C, B, and A, and thenis excreted. And similarly the fourth sequence IV of inflatable membersections is actuated with section D followed by Section C followed bysection B and then followed by Section A. Finally a fifth sequence V ofinflatable member sections is actuated with section E, followed bySection D, followed by section C, followed by Section B and followed bySection A. Thus, the prosthetic bowel 330 is emptied by first emptyingthe aborad most section and slowly working towards the orad end so thatthe pump does not have to pump the entire prosthetic bowel out at onetime.

FIGS. 12A and 12B illustrate an alternative embodiment of a prostheticbowel of the invention with a two stage orad valve. The prosthetic bowel130 includes an outer tube 131, a plurality of inflatable member pairs136, an inner tube 132 and an orad valve 137. The outer tube 131comprises a first portion 131 a constructed of a flexible, elasticmaterial coupled to a second portion 131 b constructed of a flexible,inelastic material. The inner tube 132 comprises a thin-walled,in-elastic flexible material such as polyethylene or polyurethane.Alternatively an elastic material may be used. The inside of the innertube 132 may be coated with an antibiotic surface, such as a silvercoating, to reduce bacterial growth. The inner tube 132 is attached tothe outer tube 131 at the orad end portion 133 and the aborad endportion (not shown) of the prosthetic bowel 130 (for example, bywelding) to provide an isolated conduit through which material may pass.The orad end portion 133 of the outer tube 131 includes a relativelythicker portion 138 for suturing the outer tube 131 to a small bowel oran orad section of the colon that is to remain intact. The inner tube132 defines a lumen through which material may enter from the smallbowel or small intestine and exit through the anus. The inflatablemember pairs 136, located between the inner member 131 and the secondportion 131 b of the outer member form a bowel emptying mechanism 135.The number of inflatable member pairs 136 maybe selected based on thedesired length of the prosthetic bowel 130.

The orad valve 137, located at the orad end portion 133 of theprosthetic bowel 130 between the outer tube 131 and inner tube 132,comprises a first low pressure valve 141 and a second high pressurevalve 142. The low pressure valve 141 includes two opposing inflatedmembers 141 a, 141 b inflated to a predetermined pressure. The inflatedmembers 141 a, 141 b are attached to the outer tube 131 and locatedbetween the inner tube 132 and the first portion 131 a of the outertube. The inflated members 141 a, 141 b tend to close together. (FIG.12A) When a sufficient pressure or force is created in the smallintestine from material moving from the small intestine into theprosthesis, the inflated members 141 a, 141 b open to permit the passageof material, pressing against the flexible elastic first portion of theouter tube 131 which expand under a threshold pressure. (FIG. 12B).

The high-pressure valve 142 is adjacent the low-pressure valve 141 in anaborad direction. The high-pressure valve 142 includes opposinginflatable members 142 a and 142 b located within the second portion ofthe valve 137. When inflated to a predetermined pressure, the inflatablemembers squeezes the inner tube 132 together preventing movement ofmaterial between the small intestine and the prosthetic bowel 130. Toclose the high-pressure valve 142, it is inflated by way of pumpingfluid through conduit 144 with a fluid pump such as the pump 41described with reference to FIGS. 2-11. Typically the high-pressurevalve 142 is left open when the prosthetic bowel 130 is collectingmaterials from the small intestine (FIG. 12B). The high-pressure valve142 is typically closed during or just prior to the bowel emptyingmechanism 135 being actuated (FIG. 12A). The inflatable members 142 a,142 b are inflated to a high pressure that can with stand the pressureof the bowel emptying mechanism 135 when it is actuated to move materialthrough the prosthetic bowel 130. Alternatively or in addition,inflation members such as inflation member pairs 136 may be used as ahigh-pressure valve in the two-stage valve.

Alternatively, as illustrated in FIGS. 12C and 12D the inflated members141 a′, 141 b′ are coupled through a conduit 143′ extending from theinflated members 141 a′, 141 b′ out of the outer tuber 131′, to anelastic bladder 146′. The outer tube 131′ of the prosthetic bowel 130′is relatively inelastic. When a force exceeding a predetermined pressureis applied to the inflated members 141 a′, 141 b′, for example, by apressure or by material entering the prosthetic bowel from the smallbowel, a portion of the inflation medium within the inflated members 141a′, 141 b′ is squeezed into the elastic bladder 146′ (FIG. 12D). Whenthe force is removed, the elasticity of the bladder 146′ causes thebladder 146′ to contract and squeeze the fluid out of the bladder backinto the inflated members 141 a′, 141 b′ to its original resting state(FIG. 12C). Generally, the pressure of the low-pressure valve 141′ islower than or matches the pressure exerted by the small bowel when itcontracts. Thus the low pressure valve remains closed unless a pressureis exerted on the orad side of the valve 141′. The valve 141′ tends toclose when a pressure is exerted from the aborad side in a similarmanner as described with reference to FIGS. 2-11 above with respect tothe valve 37. A high-pressure valve 142′ operates in the same way ashigh pressure valve 142 described with reference to FIGS. 12A and 12B.

FIG. 14 illustrates an alternative configuration of inflatable members156 a-e and 157 a-e of a bowel emptying mechanism 155 of an alternativeembodiment of a prosthetic bowel 150. Upper inflatable members 156 a-eare offset from the lower inflatable members 157 a-e so that material isnot stuck between opposing inflation member pairs. The inflatablemembers 156 a-e, 157 a-e may be inflated in a sequence similar to thesequence described above with respect to FIGS. 2-11 or alternativelyeach inflation member may be inflated in an aborad moving sequence.

FIG. 15 illustrates another configuration of inflatable members 166 a-dof a bowel emptying mechanism 165 of an alternative embodiment of aprosthetic bowel 160. Each inflatable member 166 a-d comprises aninflatable member wrapped in a spiral-like configuration around theinner circumference of the outer tube 162. The inflatable members 166a-d may be inflated in a sequence similar to the sequence describedabove with respect to FIGS. 2-11 and each inflation member may beinflated in an aborad moving sequence.

FIG. 19 illustrates an alternative embodiment of a prosthesis 170 of theinvention. The prosthetic bowel 170 comprises an outer tube 171, andinner tube 172 and an inflation member pair 176 located between theinner tube 172 and the outer tube 171. Waste material enters the oradend portion 173, which is coupled to the small intestine (not shown),and exits the aborad end portion 174 which is coupled to the anus (notshown). A pump 178 is controlled by a controller 180 to pump fluid froma bladder 179 through a fluid conduit 177 and into the inflation memberpair 176, and, visa versa to pump material out of the prosthetic bowel170. The prosthetic bowel 170 may be used to replace the bowel or asmall portion of the small or large bowel.

FIG. 20 illustrates an alternative configuration of an inflation member196 to be used in a prosthetic bowel 190 wherein the inflation member196 has a U-shape or a donut-like shape. The inflation member 196 islocated between an outer tube 191 and an inner tube 192 and is inflatedand deflated with an inflation medium through a conduit 199.

FIGS. 16-18F illustrate a valve-actuating device 300 according to anembodiment of the invention. The valve-actuating device 300 comprises acylinder 310 having a length Lc aligned parallel with the length Lh ofthe header 45 of the pump 41 and adjacent the valves 46 a-g. Thecylinder 310 includes a plurality of openings 320 a-g, spaced a defineddistance along the length Lc of the cylinder 310 with respect to theother openings so that each opening is aligned lengthwise with acorresponding one of the valves 46 a-g. Each opening 320 a-g is alsospaced a defined discrete distance circumferentially from the otheropenings. The cylinder 310 is coupled to a stepper motor 330 thatrotates the cylinder 310 according to instructions from the controller51 (FIG. 2) into discrete circumferential positions to interfacinglyalign a selected opening with a corresponding selected valve. Thus, thecylinder 310 may be rotated to discrete positions wherein in eachposition one of the openings 320 a-g is interfacing a corresponding oneof the valves 46 a-g to be actuated.

A valve is actuated by a peg extending out of an interfacing opening inthe cylinder 310 to engage and move the valve into an open position.Each opening 320 a-g in the cylinder 310 includes concentricallymoveable peg 321 a-g respectively. Each of the pegs 321 a-g is capableof being partially advanced in a circumferential direction out of thecorresponding opening 320 a-g in the cylinder 310. When interfacing witha corresponding valve 46 a-g, a corresponding peg 321 a-g may beadvanced to engage and open the corresponding valve 46 a-g to open it.

Once a valve is selected and the controller 51 instructs the steppermotor 330 to rotatably position the cylinder 310 accordingly, anactuating rod 323 is advanced through the cylinder 310 to engage andadvance the corresponding aligned, interfacing peg out of the cylinder310 to open the corresponding valve.

The actuating rod 323 slidably extends axially through an axial opening313 in the cylinder 310. The rod 323 is coupled to a solenoid 328 thatmoves the rod 323 between two positions: a first resting position (FIG.16-16A, FIGS. 18-18F) and a second valve actuating position (FIG.17-17A). The solenoid 328 advances and retracts the rod 323 to and froma valve actuating position. The actuating rod 323 moves in a directiongenerally perpendicular to the circumferential sliding direction of thepegs 321 a-g. The actuating rod 323 includes a central rod 324 and aplurality of staggered fins 325 a-g having cammed surfaces 326 a-g. Inthe first position, the fins 325 a-g are staggered in a lengthwiserelationship between the valves 46 a-g and a second position, the fins325 a-g are generally aligned in a lengthwise relationship with thevalves 46 a-g. The cammed surfaces 326 a-g are arranged so that when therod 323 is advanced to the second position, a corresponding one of thecammed surfaces 326 a-g will engage a corresponding one of the pegs 321a-g to move the corresponding one of the pegs 321 a-g circumferentiallyout of a corresponding one of the openings 320 a-g.

The axial opening 313 through the cylinder 310 includes a central rodportion 314 for receiving the rod 323 and a fin portion 315 forreceiving in the fins 325 a-g. The central rod portion 314 extendsaxially through the cylinder 310. The fin portion 315 of the axialopening 313 includes open portions 316 a-g staggered in a lengthwiserelationship between the valves 46 a-g. Each open portion 316 a-g isopen within the rod opening 313 about the circumference of the cylinder310 so that when the rod 323 is in the first position, the cylinder 310is free to rotate without interference of the fins 325 a-g. The finportion 315 also includes a plurality of slits 317 a-g wherein each slitextends longitudinally through the cylinder, between each of the openportions 316 a-g and perpendicularly through a corresponding one of theopenings 320 a-g.

The fins 325 a-g are aligned in a position with the circumferentiallyextending top portions facing the header 45. The cylinder 310 may berotated when the rod 323 and fins 325 a-g are in the first position. Thecylinder 310 when rotated to one of its discrete positions aligns acorresponding slit with the fins so that in the second position the finsadvance through that slit. When the fins 325 a-g are moved into thesecond position, the fins 325 a-g extend through the slit correspondingto the opening that is positioned in alignment with a correspondingvalve. In each discrete position the fins 325 a-g are aligned with aslit permitting the corresponding fin to slide into the opening andengage the pin moving the pin out of the opening engaging the correspondvalve with which it is aligned, thus actuating the corresponding valve.Each peg 321 a-g is biased by a corresponding spring (329 a only isshown) into a position circumferentially into the opening so that whenthe fins are retracted (e.g. FIG. 18), the pin moves back into theopening.

The controller 51 controls the timing and actuation of the cylinder 310rotation and the solenoid 328 positioning. Referring to FIG. 16, thecylinder 310 is rotated to a position in which none of the pegs arealigned with valve 36 a. The rod 323 is in a first position in which thecylinder 310 may rotate freely. The cylinder 310 is then rotated asillustrated in FIG. 17 so that the opening 321 a is aligned with thevalve 46 a. The rod 323 is advanced so that the fins 325 a-g extendthrough the slit 317 a. Fin 325 a extends into the opening 320 a that isaligned with the slit 325 a and the cammed surface 326 a of the fin 325a engages the peg 321 a and advances it out of the opening 320 a toactuate valve 46 a. The valve 46 a is opened and the pump pumps fluidfrom the reservoir 49 into the inflatable member pair 36 a. Asillustrated in FIG. 18, the rod 323 is then retracted releasing the peg321 a, which is biased by spring 329 a into the cylinder opening 320 a,and the valve 46 a is closed, leaving the inflation member pair 36 ainflated.

While the invention has been described with reference to particularembodiments, it will be understood to one skilled in the art thatvariations and modifications may be made in form and detail withoutdeparting from the spirit and scope of the invention.

For example the peristalsis organ of the invention may be used in aprosthetic stomach organ or prosthetic pylorus such as, for examplethose disclosed in the U.S. application entitled “Stomach Prosthesis”,filed on even date herewith, which is incorporated into this patentapplication by reference.

1. A method for moving material through a digestive tract of a patient,the method comprising: providing a prosthetic organ having a conduit forthe movement of the material therethrough and a plurality of expandablemembers, wherein the conduit is isolated from the expandable members,the conduit having an orad end an aborad end and a length extendingtherethrough; and sequentially inflating the expandable members to movethe material through the conduit in an aborad direction withoutcontacting the expandable member.